Earthquake off B.C. coast precursor to the Big One?

Alina Seagal

Daily BrewOctober 28, 2012

Last night's powerful quake that struck off Haida Gwaii was the largest one since 1949 in Canada. The magnitude 7.7 earthquake off British Columbia's north-central coast hit at 8:04 p.m. PT, followed by a string of aftershocks, evacuations and tsunami warnings.

Though the warnings were cancelled on Sunday morning, the residents still remain rattled by last night's events.

Brent Ward, an earth scientist at Simon Fraser University, told the CBC that this was the largest earthquake to hit Canada since 1949, when a magnitude 8.1 tremor was recorded in the same area.

Ward said the area is known as the Queen Charlotte fault, where the earth's plates slide horizontally across each other in a strike-slip action, similar to what happens along California's San Andreas fault.

Only this August, two geological studies indicated that the Pacific Coast is one of the prime locations for a massive earthquake, that might hit within the next 50 years.

"Over the past 10,000 years, there have been 19 earthquakes that extended along most of the margin, stretching from southern Vancouver Island to the Oregon-California border," said Chris Goldfinger, who led a team of researchers working on one of the studies, according to the Postmedia News.

"These would typically be of a magnitude from about 8.7 to 9.2 — really huge earthquakes."

Goldfinger's team suggested that, in some of the most vulnerable areas, the likelihood of a disastrous event is up to 37 per cent.

Though unlike the predictions made in the studies, stating that southern British Columbia is at risk, last night's earthquake struck further north and caused no devastation, according to initial reports.

Aside from more than 10 aftershocks, the initial jolting from the quake last night lasted for up to a minute for those located near its epicentre. No serious injuries or major damages have been reported so far, though power outages in Haida Gwaii reportedly lasted for more than an hour, according to the CBC.

Tsunami warnings for some of the central B.C. coast, the North Coast, the Haida Gwaii islands, parts of Alaska and Hawaii were downgraded to advisory status on Sunday morning and lifted a few hours later. Later this Sunday, a minor earthquake has rattled downtown Los Angeles.

"It looks like the damage and the risk is at a very low level, we are very grateful for that," said Shirley Bond, British Columbia's minister responsible for emergency management, according to the Globe and Mail.